Lecture 15: Arthropods 2

Question 1

Groups of Myriaapods

Answer 1

1. Chilopoda (centipedes- one pair of appendages/segment)

2. Diplopoda (milipedes- two pairs of appendages/segments)

Question 2

Centipedes

Answer 2

carnivorous

300 sp

Question 3

Milipedes

Answer 3

herbivore, derivores

11,000 sp

Question 4

Three groups of Chelicerates

Answer 4

1. Merostomata: horseshoe crabs
2. Pycngoids: sea spiders
3. Arachnids: spiders, scorpions, pseudoscorbians etc.

Question 5

Crustaceans

Answer 5

1. Isopods (wood lice)
2. Theocostraca (barnacles)
3. Decapods (shrimps, lobsters, cray fish)
4. Cladocerans (water fleas)

Question 6

Cephalothorax

Answer 6

antenna + peripods (actual limbs)

Question 7

Abdomen

Answer 7

pleopods (used for swimming), uropods and telson

Question 8

insects respiratory system

Answer 8

air sacs on exoskeleton to allow for respiration with trachea and spicules

Question 9

decapods respiratory system

Answer 9

have gills

Question 10

spiders + scorpions respiratory system

Answer 10

have book lungs and lamellae surrounded by muscles

Question 11

spider circulatory system

Answer 11

ventral portion of abdomen

Question 12

insect circulatory system

Answer 12

multiple hearts

Question 13

body plan of insects

Answer 13

head, thorax, abdomen

Question 14

evolutionary success of insects include

Answer 14

• diversity of mouthparts for different feeding types
• ability to fly
• new mechanism for delivering oxygen into internal tissues

Question 15

Hormones

Answer 15

chemical messengers secreted by endocrine cells

distributed by blood

Question 16

How to hormones work?

Answer 16

affect expression of gene
alter activity of enzyme
change permeability of membrane

Question 17

autocrine signals

Answer 17

act on same cell that secretes hormone

Question 18

paracrine signals

Answer 18

diffuse locally and work on neighbouring cells

Question 19

endocrine signals

Answer 19

carried between cells by blood and other fluids

Question 20

PTTH

Answer 20

hormone that is released by prothoracic gland in brain

Question 21

ecdysone

Answer 21

signals moulting in insects
released by PTTH
maintains insect in larvel stages unless PTTH is present